Figure 304
-Dll Is a Gene Known to Direct Limb Development

Multiple Choice

$\begin{array} { l l } { \text { Phylum } } & { \text { Dll Activity in Developing } } \\&\text { Appendages }\\ \text {Annelida}&\text {Yes}\\ \text {Arthropoda}&\text {Yes}\\ \text {Chordata}&\text {No}\\ \text {Echinodermata}&\text {No}\\ \text {Mollusca}&\text {Yes}\end{array}$ Figure 30.4
-Dll is a gene known to direct limb development in the fruit fly. Researchers studying this gene have found that it is also expressed in developing appendages in animals from many other phyla as well, supporting the hypothesis that all animal appendages may be homologous. However, suppose researchers looking at Dll activity had instead found the results shown in Figure 30.4.
What would these results suggest?

A) All animal appendages are homologous.
B) Appendages coevolved with segmentation.
C) Dll is not actually involved in appendage development.
D) Appendages evolved separately in protostomes and deuterostomes.